Strong Electronic Interaction Enhanced Electrocatalysis of Metal Sulfide Clusters Embedded Metal–Organic Framework Ultrathin Nanosheets toward Highly Efficient Overall Water Splitting

• Published in: Advanced science 2020-10, Vol.7 (20), p.2001965-n/a
• Main Authors: Zhao, Ming, Li, Wei, Li, Junying, Hu, Weihua, Li, Chang Ming
• Format: Article
• Language: English
• Subjects: electronic interactions; Ligands; metal sulfide clusters; metal–organic frameworks; Nanoparticles; Scanning electron microscopy; ultrathin nanosheets; water splitting
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202001965

Unique metal sulfide (MS) clusters embedded ultrathin nanosheets of Fe/Ni metal–organic framework (MOF) are grown on nickel foam (NiFe‐MS/MOF@NF) as a highly efficient bifunctional electrocatalyst for overall water splitting. It exhibits remarkable catalytic activity and stability toward both the oxygen evolution reaction (OER, ƞ = 230 mV at 50 mA cm−2) and hydrogen evolution reaction (HER, ƞ = 156 mV at 50 mA cm−2) in alkaline media, and bi‐functionally catalyzes overall alkaline water splitting at a current density of 50 mA cm−2 by 1.74 V cell voltage without iR compensation. The enhancement mechanism is ascribed to the impregnated metal sulfide clusters in the nanosheets, which not only promote the formation of ultrathin nanosheet to greatly enlarge the reaction surface area while offering high electric conductivity, but more importantly, efficiently modulate the electronic structure of the catalytically active atom sites to an electron‐rich state via strong electronic interaction and strengthen the adsorption of oxygenate intermediate to facilitate fast electrochemical reactions. This work reports a highly efficient HER/OER bifunctional electrocatalyst and may shed light on the rational design and synthesis of uniquely structured MOF‐derived catalysts. Fe/Ni‐based metal–organic framework ultrathin nanosheets with embedded metal sulfide clusters exhibit remarkable catalytic activity and stability toward both the oxygen evolution reaction and hydrogen evolution reaction in alkaline media. The metal sulfide clusters efficiently modulate the electronic structure of the catalytically active layer to an electron‐rich state via strong electronic interaction to facilitate the electrochemical reactions.